1. Technical Field
The invention relates to a process for manufacturing products of mineral wool in accordance with the opening parts of claim 1, as well as monolayer and multilayer products in accordance with the opening parts of claims 19 and 21.
2. Related Art
Various processes for manufacturing mineral fibers are known and in use, such as fiberization by internal centrifugation (so-called TEL technique), external centrifugation processes such as the cascade centrifugation process (so-called REX technique), blast drawing process etc. In all of these known processes, the fibers to be produced are introduced by means of large flow rates of a mixture of air and combustion gases, which are necessary for fiberization, into a collection chamber, often referred to as a chute. For producing bonded mineral wool products, the fibers are provided with a binder while passing the chute. In the chute, moreover, other process-relevant substances may be added, such as dust binding agents, hydrophobizing agent, and the like.
The fibers thus obtained are collected and separated from the accompanying air/gas flow on a moving, perforated element constituting one of the delimitations of the chute. When the fibers are collected on the perforated element, endless mats are formed which predetermine the corresponding properties of the subsequent product in respect of weight per unit area, width, fiber orientation, and homogeneity. These properties cannot be modified in essence any more later on so that orientations of the fibers in the mat or inhomogeneities in the subsequent product generated upon collection from the chute are predetermined unless the mat is later on split or doubled, or separated into laterally adjacent webs.
In cases of a constant fiber supply, the weight per unit area is influenced by varying the velocity of the perforated collection element, with the fiber orientation being substantially laminar. By “laminar” it is here understood that the fibres are oriented substantially parallel to a surface, usually the supporting surface thereof. In the course of the production of the mat, the entire air/gas quantity must pass through the mat under formation. Depending on the weight per unit area and the available evacuation area, different vacuum pressures are required in the evacuation.